Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D403/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00
  • C07D403/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00 containing two hetero rings
  • C07D403/04—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00 containing two hetero rings directly linked by a ring-member-to-ring-member bond
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D257/00—Heterocyclic compounds containing rings having four nitrogen atoms as the only ring hetero atoms
  • C07D257/02—Heterocyclic compounds containing rings having four nitrogen atoms as the only ring hetero atoms not condensed with other rings
  • C07D257/04—Five-membered rings
  • C07D257/06—Five-membered rings with nitrogen atoms directly attached to the ring carbon atom

Definitions

• Rajappa et al. Tetrahedron, 29, 1299 (1973), describes the reaction of anthranilic acid with a bicyclic imino ether to give a complex tetracyclic system which contains the quinazolinone structure.
• Rajappa et al. were interested in other questions and provided no details with regard to this process or any background leading up to their use of it. It is noted, however, that their process was limited to the acid (anthranilic) and heat alone was sufficient to bring about the cyclization involved in the preparation of the Rajappa compounds.
• the procedure involves a process for the preparation of quinazolinones of the formula ##STR1## wherein X represents hydrogen or one or two methyl, halogen or methoxy groups or a methylenedioxy group, and the alkali metal, ammonium and amine salts thereof, which comprises:
• the amines referred to above with regard to salts or the cyclization are mono-, di- and tri-alkylamines wherein each alkyl group contains up to four carbon atoms.
• the present invention further encompasses the novel imino ether and formamidine intermediates used in the present process.
• the anthranilic acid derivative and the imino ether (used either as the compound itself or as prepared in situ) are heated in an inert solvent such as carbon tetrachloride, 2-propanol or other solvents and the indicated mixed formamidine forms.
• an inert solvent such as carbon tetrachloride, 2-propanol or other solvents and the indicated mixed formamidine forms.
• Z or OZ contains nitrogen, the formamidine cyclizes directly to the desired product but, when esters are used (Z is alkyl), it is necessary to treat the formamidine with base either with or without isolation of the formamidine.
• Z is alkyl and the formamidine is isolated, it is then treated with base in an appropriate solvent to give the desired quinazolinone.
• Hydroxylic solvents such as methanol or 2-propanol are preferred although other solvents such as toluene and dimethylformamidine can be used.
• Bases which can be used in the cyclization step, with or without isolation of the formamidine, include sodium carbonate, sodium hydroxide, sodium methoxide, sodium t-butoxide, ammonium hydroxide, n-propylamine, diethylamine, trimethylamine and triethylamine. As noted earlier, when base is present in the reaction mixture, the product is obtained as the tetrazole salt. Heating is optional for the cyclization step.
• the imino ether used in the first step of the process is prepared by heating 5-aminotetrazole and an appropriate trialkoxymethane in excess trialkoxymethane or in an inert solvent such as hexane, carbon tetrachloride or N,N-dimethylformamide.
• the imino ether can be specifically isolated and then used in the present process. However, it hydrolyzes rapidly on exposure to atmospheric moisture so that it is usually preferable to prepare the imino ether in situ and use it immediately in the process of the invention.
• this reactant may not be named specifically in many of the examples but it is actually formed in the reaction mixture and then reacts further as described. The examples involved should thus be read with this fact in mind.
• a preferred embodiment of the present invention involves carrying out the process using anthranilic acid esters (i.e., Z is alkyl of 1-4 carbon atoms).
• a further preferred embodiment involves the use of methyl anthranilate in the process, with the imino ether prepared in situ and the entire process carried out in a single pot.
• this further preferred embodiment of the present invention specifically directed to the preparation of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone, it is possible to combine the preparation of the imino ether with the process described earlier and carry out the complete synthesis of the 3(4H)-quinazolinone without isolating any of the intermediates.
• triethoxymethane, 5-aminotetrazole and methyl anthranilate are mixed in an inert solvent and heated.
• useful solvents are 2-propanol, carbon tetrachloride, toluene or ethyl acetate.
• the formamidine described earlier forms in the reaction mixture and base is then added as discussed earlier and the mixture is heated to bring about cyclization and give the desired 4(3H)-quinazolinone.
• a mixture was prepared from 50 g of 5-aminotetrazole, 347 g of triethoxymethane and 500 ml of hexane and this was heated under nitrogen so that distillation took place at a moderate rate (head temperature about 60°-68° C.). Distillate was collected over a period of 6 hours with hexane being replaced in the reaction mixture as necessary. The mixture was then cooled to room temperature and the fine white needles that formed were collected by filtration, washed with hexane and vacuum oven dried with heating to give 5-(ethoxymethyleneamino)tetrazole. This material hydrolyzes rapidly on exposure to atmospheric moisture so that it should be used promptly for any further reactions desired or it should be stored using appropriate conditions.
• a mixture was prepared from 12.2 g of 5-aminotetrazole monohydrate, 71.3 g of triethoxymethane, 22.3 g of methyl anthranilate and 100 ml of carbon tetrachloride and this was refluxed under nitrogen with stirring for 16 hours. The mixture was then cooled to room temperature and the white crystals which formed were separated by filtration, washed with carbon tetrachloride and dried to give N 1 -(1H-tetrazol-5-yl)-N 2 -(2-carbomethoxyphenyl)formamidine melting at about 199°-200° C.
• a mixture was prepared from 9.5 g of 5-aminotetrazole, 16.5 g of triethoxymethane and 50 ml of N,N-dimethylformamide and heated under nitrogen and a solution of 16.9 g of methyl anthranilate in 15 ml of N,N-dimethylformamide was added to the hot mixture and stirred for 15 minutes. The mixture was then cooled to room temperature and stirred for 16 hours.
• a mixture was prepared from 2.9 g of the sodium salt of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolin-4-one, 25 ml of methanol and 15 ml of water and stirred at room temperature. To this mixture was added 4 ml of 3N hydrochloric acid and stirring was continued for 15 minutes. The white solid which formed was separated by filtration, washed with water and vacuum oven dried to give 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone which was idential with authentic material.
• a cooled (0° C.) slurry was prepared from 10 g of N 1 -(1H-tetrazol-5-yl)-N 2 -(2-carbomethoxyphenyl)formamidine and 25 ml of water and this was stirred while 8.2 ml of 5N sodium hydroxide was added dropwise.
• the mixture was brought to room temperature and 200 ml of 2-propanol was added. It was then heated to 70° C., a further 90 ml of 2-propanol was added, and the mixture was stirred for 4 hours at 70° C. It was then cooled to room temperature and stirred for 16 hours.
• the white crystals which formed were separated by filtration and washed with aqueous 2-propanol and vacuum oven dried to give the sodium salt of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone.
• a solution was prepared from 0.3 g of N 1 -(1H-tetrazol-5-yl)-N 2 -(2-carbomethoxyphenyl)formamidine and 10 ml of N,N-dimethylformamide.
• a slurry of 67 mg of sodium methoxide in 1.4 ml of N,N-dimethylformamide was added and the mixture was stirred under nitrogen for 30 minutes.
• the solvent was then evaporated under reduced pressure to give the sodium salt of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone.
• a mixture was prepared from 0.3 g of N 1 -(1H-tetrazol-5-yl)-N 2 -(2-carbomethoxyphenyl)formamidine and 15 ml of methanol and cooled to 0° C. under positive pressure of nitrogen. Solid sodium methoxide (0.66 g) was added portionwise and the mixture was stirred for 15 minutes. The solvent was evaporated in vacuo to give crude sodium salt of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone (93% pure by HPLC).
• a mixture was prepared from 0.4 g of N 1 -(1H-tetrazol-5-yl)-N 2 -(2-carbomethoxyphenyl)formamidine and 40 ml of toluene and this was heated to 60° C. under nitrogen. A solution of 20% sodium t-butoxide in tetrahydrofuran (0.7 ml) was added, the mixture was stirred at 60° C. for 1 hour, and then cooled to room temperature. The off-white solid which formed was separated by filtration, washed with hexane and vacuum oven dried to give crude sodium salt of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone with a purity of greater than 90% as shown by HPLC.
• N 1 -(1H-Tetrazol-5-yl)-N 2 -(2-carbomethoxyphenyl)formaidine (5 g) was mixed with 25 ml of 2-propanol. The resulting slurry was stirred at room temperature and 2 g of triethylamine was added. The mixture was heated at reflux for 24 hours and then cooled to room temperature. The white crystals which formed were separated by filtration, washed with 2-propanol and dried to give the triethylammonium salt of 3-(1H-tetrazol-5-yl)-4(3H)-quinazolinone melting at about 112°-115° C. Evaporation of the solvent from the filtrate in vacuo gave a residue which was triturated with carbon tetrachloride, filtered and dried to give additional crude triethylammonium salt.
• a mixture was prepared from 10 g of 5-aminotetrazole, 18.2 g of triethoxymethane, 18 g of methyl anthranilate and 90 ml of 2-propanol and this was heated at 70° C. under nitrogen and stirred for 1.5 hours. The mixture was then cooled to room temperature, 23 ml of distilled water was added, and the resulting mixture was then stirred for 15 minutes before 24 ml of 5N aqueous sodium hydroxide was added. The resulting mixture was first stirred at room temperature for 15 minutes and then heated to reflux. A clear pale yellow solution resulted and 180 ml of 2-propanol was added at such a rate that the temperature remained above 70° C.
• a mixture was prepared from 10 g of 5-aminotetrazole and 50 ml N,N-dimethylformamide. This was heated to 100° C. and 17 g of triethoxymethane was added. The resulting mixture was stirred at 100° C. under nitrogen for 2 hours and then a solution of the ammonium salt of anthranilic acid (prepared from 16 g of anthranilic acid and 7.8 ml of 14.8M ammonium hydroxide in methanol, followed by removal of the methanol) in 40 ml of N,N-dimethylformamide was added. The mixture was stirred for 1 hour at 100° C., then cooled to room temperature and finally cooled in an ice bath to induce crystallization.
• anthranilic acid prepared from 16 g of anthranilic acid and 7.8 ml of 14.8M ammonium hydroxide in methanol, followed by removal of the methanol
• a solution was prepared from 11.7 g of methyl anthranilate and 80 ml of anhydrous methanol and cooled to 0° C. under nitrogen. To this stirred solution was added 10 g of 5-(ethoxymethyleneamino)tetrazole as a solid. The reaction mixture was stirred for 20 minutes and then 14.2 ml of 5N sodium hydroxide was added and stirring was continued for 10 minutes. The mixture was filtered to remove some insoluble solid and the solvent was evaporated from the filtrate in vacuo to leave a residual glassy solid. This was taken up in water/2-propanol (35 ml, 1:1) and heated to 70° C. An additional 80 ml of 2-propanol was added and heating was continued for 20 minutes.
• a mixture was prepared from 12 g of 5-aminotetrazole monohydrate, 36.5 g of triethoxymethane, 38.5 g of methyl anthranilate and 100 ml of ethyl acetate under a positive pressure of nitrogen. The mixture was heated at 60° C. for 6 hours and then 50 ml of 2.3N sodium hydroxide was added to the hot solution. Agitation was discontinued to allow phase separation and the organic phase was removed. To the hot aqueous phase was added 300 ml of 2-propanol and this mixture was stirred for 2 hours as precipitation occurred.
• a mixture was prepared from 10 g of 5-aminotetrazole, 19.6 g of triethoxymethane, 19.8 g of methyl anthranilate and 150 ml of toluene. This heterogeneous mixture was heated until distillate appeared and slow distillation was continued for 5 hours with replenishment of the toluene in the reaction vessel as necessary. The mixture was then cooled to 65° C. and 6.4 g of anhydrous sodium carbonate was added followed by the slow addition of 50 ml of water. The mixture was then heated for 30 minutes and the aqueous phase was separated. This aqueous phase was heated to 80° C. and to the hot mixture was slowly added 300 ml of 2-propanol.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Plural Heterocyclic Compounds (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Pyrrole Compounds (AREA)
• Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)
• Nitrogen Condensed Heterocyclic Rings (AREA)
• Cosmetics (AREA)

Priority Applications (19)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24445080

Family Applications (1)

Country Status (19)

Cited By (3)

Families Citing this family (1)

Citations (5)

Family Cites Families (1)

• 1984
  • 1984-05-15 US US06/610,456 patent/US4644065A/en not_active Expired - Fee Related
• 1985
  • 1985-05-10 ZA ZA853570A patent/ZA853570B/xx unknown
  • 1985-05-10 CA CA000481295A patent/CA1252094A/en not_active Expired
  • 1985-05-10 IL IL75162A patent/IL75162A/xx unknown
  • 1985-05-13 EP EP85105877A patent/EP0161661B1/en not_active Expired - Lifetime
  • 1985-05-13 GR GR851154A patent/GR851154B/el unknown
  • 1985-05-13 FI FI851886A patent/FI88720C/fi not_active IP Right Cessation
  • 1985-05-13 DE DE8585105877T patent/DE3580698D1/de not_active Expired - Fee Related
  • 1985-05-13 AU AU42420/85A patent/AU570604B2/en not_active Ceased
  • 1985-05-13 AT AT85105877T patent/ATE58733T1/de not_active IP Right Cessation
  • 1985-05-13 NZ NZ212054A patent/NZ212054A/en unknown
  • 1985-05-13 ES ES543102A patent/ES8603484A1/es not_active Expired
  • 1985-05-14 NO NO851930A patent/NO159792C/no unknown
  • 1985-05-14 HU HU851812A patent/HU193755B/hu not_active IP Right Cessation
  • 1985-05-14 DK DK214185A patent/DK214185A/da not_active Application Discontinuation
  • 1985-05-14 KR KR1019850003273A patent/KR880002627B1/ko not_active IP Right Cessation
  • 1985-05-14 JP JP60100651A patent/JPS60248685A/ja active Pending
  • 1985-05-14 PT PT80454A patent/PT80454B/pt not_active IP Right Cessation
  • 1985-05-15 PH PH32274A patent/PH21159A/en unknown

Patent Citations (5)

Non-Patent Citations (12)

Also Published As

Similar Documents

Legal Events